This invention relates to a device for conveying a piece for forming a bottle-shaped container and, more particularly, to a steeply inclined conveyor for lifting a plurality of injection-molded pieces and, immediately after cooling or cooling and stocking, conveying them upwardly one by one to the piece supplying position of a blow-molding machine.
A bottle-shaped blow-molded thin transparent container of biaxially oriented plastic is fabricated by heating a closed bottom cylindrical piece of polyethylene terephthalate resin and biaxially orienting it longitudinally and laterally in the mold of a blow molding machine. Since numerous pieces are simultaneously molded from an injection molding machine and are respectively fed in the state directed at random, it is not easy to supply the pieces one by one to a biaxial orientation blow molding machine to meet the molding speed of the blow molding machine. As the capacity of the piece molding machine is, in addition, not normally equal to that of the blow molding machine, numerous pieces thus injection-molded are temporarily stocked and are then aligned and supplied sequentially as required.
It is, therefore, necessary that a device for conveying the pieces thus injection-molded to the blow molding machine affords to loop the numerous pieces before supplying to the blow molding machine for molding the pieces sequentially at a predetermined time interval into bottle-shaped containers. It is also required to afford a time needed to cool the pieces which are not immediately after injection-molding. Accordingly, the piece conveying device must employ a relatively long conveying distance.
In the meantime, it is the most simple and exact method to hold the piece while lifting it via the flange formed at the neck portion of the piece in an upwardly opening position and to lower it by means of the self-weight of the piece as maintained vertically in the upwardly opening position on an oblique surface to thereby supply it to the mold of a blow molding machine. However, both the injection molding and blow molding machines are normally installed directly on the floor in a factory. It is consequently impossible in fact to dispose the mold of the blow molding machine higher than that of the injection molding machine and accordingly lower than the piece pickup position. Furthermore, as the piece conveying device necessitates relatively long conveying distance of the piece, it is also difficult to provide the piece conveying path only with the oblique surface.
It has to, therefore, devise certain means for conveying the pieces as retained vertically in the upwardly opening attitude by suitable means, via appropriate feeding means. However, it will not only introduce an expensive facility cost, but also result in complicated maintenance and management with excessive man hours being necessary to install such a complicated means over the entire piece conveying route of relatively long distance.